Class CheckSumFilter

All Implemented Interfaces:
Result, Receiver

public class CheckSumFilter extends ProxyReceiver
A filter to go on a Receiver pipeline and calculate a checksum of the data passing through the pipeline. Optionally the filter will also check any checksum (represented by a processing instruction with name SIGMA) found in the file.

The checksum takes account of element, attribute, and text nodes only. The order of attributes within an element makes no difference.

  • Field Details

  • Constructor Details

    • CheckSumFilter

      public CheckSumFilter(Receiver nextReceiver)
  • Method Details

    • setCheckExistingChecksum

      public void setCheckExistingChecksum(boolean check)
      Ask the filter to check any existing checksums found in the file
      Parameters:
      check - true if existing checksums are to be checked
    • startDocument

      public void startDocument(int properties) throws XPathException
      Description copied from class: ProxyReceiver
      Start of a document node.
      Specified by:
      startDocument in interface Receiver
      Overrides:
      startDocument in class ProxyReceiver
      Parameters:
      properties - bit-significant integer indicating properties of the document node. The definitions of the bits are in class ReceiverOption
      Throws:
      XPathException - if an error occurs
    • append

      public void append(Item item, Location locationId, int copyNamespaces) throws XPathException
      Append an arbitrary item (node or atomic value) to the output
      Specified by:
      append in interface Receiver
      Overrides:
      append in class ProxyReceiver
      Parameters:
      item - the item to be appended
      locationId - the location of the calling instruction, for diagnostics
      copyNamespaces - if the item is an element node, this indicates whether its namespaces need to be copied. Values are ReceiverOption.ALL_NAMESPACES; the default (0) means
      Throws:
      XPathException - if an error occurs
    • characters

      public void characters(UnicodeString chars, Location locationId, int properties) throws XPathException
      Character data
      Specified by:
      characters in interface Receiver
      Overrides:
      characters in class ProxyReceiver
      Parameters:
      chars - The characters
      locationId - provides information such as line number and system ID.
      properties - Bit significant value. The following bits are defined:
      DISABLE_ESCAPING
      Disable escaping for this text node
      USE_CDATA
      Output as a CDATA section
      Throws:
      XPathException - if an error occurs
    • startElement

      public void startElement(NodeName elemName, SchemaType type, AttributeMap attributes, NamespaceMap namespaces, Location location, int properties) throws XPathException
      Notify the start of an element
      Specified by:
      startElement in interface Receiver
      Overrides:
      startElement in class ProxyReceiver
      Parameters:
      elemName - the name of the element.
      type - the type annotation of the element.
      attributes - the attributes of this element
      namespaces - the in-scope namespaces of this element: generally this is all the in-scope namespaces, without relying on inheriting namespaces from parent elements
      location - an object providing information about the module, line, and column where the node originated
      properties - bit-significant properties of the element node. If there are no relevant properties, zero is supplied. The definitions of the bits are in class ReceiverOption
      Throws:
      XPathException - if an error occurs
    • endElement

      public void endElement() throws XPathException
      End of element
      Specified by:
      endElement in interface Receiver
      Overrides:
      endElement in class ProxyReceiver
      Throws:
      XPathException - if an error occurs
    • processingInstruction

      public void processingInstruction(String target, UnicodeString data, Location locationId, int properties) throws XPathException
      Processing Instruction
      Specified by:
      processingInstruction in interface Receiver
      Overrides:
      processingInstruction in class ProxyReceiver
      Parameters:
      target - The PI name. This must be a legal name (it will not be checked).
      data - The data portion of the processing instruction
      locationId - provides information such as line number and system ID.
      properties - Additional information about the PI.
      Throws:
      XPathException - if an error occurs
    • isChecksumFound

      public boolean isChecksumFound()
      Ask whether a checksum has been found
      Returns:
      true if a checksum processing instruction has been found (whether or not the checksum was correct)
    • getChecksum

      public int getChecksum()
      Get the accumulated checksum
      Returns:
      the checksum of the events passed through the filter so far.
    • isChecksumCorrect

      public boolean isChecksumCorrect()
      Ask if a correct checksum has been found in the file
      Returns:
      true if a checksum has been found, if its value matches, and if no significant data has been encountered after the checksum